
#ifndef __M_CHANNEL_H__
#define __M_CHANNEL_H__
#include "muduo/net/TcpConnection.h"
#include "muduo/proto/codec.h"
#include "muduo/proto/dispatcher.h"
#include "../mqcommon/mq_logger.hpp"
#include "../mqcommon/helper.hpp"
#include "../mqcommon/mq_msg.pb.h"
#include "../mqcommon/mq_proto.pb.h"
#include "mq_consumer.hpp"
#include <iostream>
#include <mutex>
#include <condition_variable>
#include <unordered_map>



namespace chenmq
{
    typedef std::shared_ptr<google::protobuf::Message> MessagePtr;
    using ProtobufCodecPtr = std::shared_ptr<ProtobufCodec>;
    using basicConsumeResponsePtr = std::shared_ptr<basicConsumeResponse>;
    using basicCommonResponsePtr = std::shared_ptr<basicCommonResponse>;
    class Channel
    {
    public:
        using ptr = std::shared_ptr<Channel>;

        Channel(const muduo::net::TcpConnectionPtr& conn, const ProtobufCodecPtr& codec)
            :_cid(UUIDHelper::uuid()),_conn(conn), _codec(codec)
        {}

        ~Channel()
        {
            basicCancel();
        }

        std::string cid()
        {
            return _cid;
        }

        bool openChannel()
        {
            std::string rid = UUIDHelper::uuid(); //获得请求id
            openChannelRequest req;
            req.set_rid(rid);
            req.set_cid(_cid);
            _codec->send(_conn, req);
            
            basicCommonResponsePtr resp = waitResponse(rid);
            return resp->ok();
        }

        void closeChannel()
        {
            std::string rid = UUIDHelper::uuid();
            closeChannelRequest req;
            req.set_rid(rid);
            req.set_cid(_cid);
            _codec->send(_conn, req);
            waitResponse(rid);
            return;
        }

        //声明交换机
        bool declareExchange(const std::string& name, ExchangeType type, bool durable, bool auto_delete,
                            google::protobuf::Map<std::string, std::string>& args)
        {
            std::string rid = UUIDHelper::uuid();
            declareExchangeRequest req;
            req.set_rid(rid);
            req.set_cid(_cid);
            req.set_exchange_name(name);
            req.set_exchange_type(type);
            req.set_durable(durable);
            req.set_auto_delete(auto_delete);
            req.mutable_args()->swap(args);

            _codec->send(_conn, req);
            basicCommonResponse resp = waitResponse(rid);
            return resp->ok();
        }

        //删除交换机
        void deleteExchange(const std::string& name)
        {
            std::string rid = UUIDHelper::uuid();
            deleteExchangeRequest req;
            req.set_rid(rid);
            req.set_cid(_cid);
            req.set_exchange_name(name);
            _codec->send(_conn, req);
            waitResponse(rid);
            return ;
        }

        bool declareQueue(const std::string& qname, bool qdurable, bool qexclusive, bool qauto_delete,
                         google::protobuf::Map<std::string, std::string>& qargs)
        {
            std::string rid = UUIDHelper::uuid();
            declareQueueRequest req;
            req.set_rid(rid);
            req.set_cid(_cid);
            req.set_queue_name(qname);
            req.set_durable(qdurable);
            req.set_auto_delete(qauto_delete);
            req.set_exclusive(qexclusive);
            req.mutable_args()->swap(qargs);
            _codec->send(_conn, req);
            basicCommonResponsePtr resp = waitResponse(rid);
            return resp->ok();            
        }

        void deleteQueue(const std::string& qname)
        {
            std::string rid = UUIDHelper::uuid();
            deleteQueueRequest req;
            req.set_rid(rid);
            req.set_cid(_cid);
            req.set_queue_name(qname);
            _codec->send(_conn, req);
            waitResponse(rid);
            return ;
        }

        bool queueBind(
            const std::string &ename, 
            const std::string &qname, 
            const std::string &key) {
            std::string rid = UUIDHelper::uuid();
            queueBindRequest req;
            req.set_rid(rid);
            req.set_cid(_cid);
            req.set_exchange_name(ename);
            req.set_queue_name(qname);
            req.set_binding_key(key);
            _codec->send(_conn, req);
            basicCommonResponsePtr resp = waitResponse(rid);
            return resp->ok();
        }

        void queueUnBind(const std::string &ename, const std::string &qname) {
            std::string rid = UUIDHelper::uuid();
            queueUnBindRequest req;
            req.set_rid(rid);
            req.set_cid(_cid);
            req.set_exchange_name(ename);
            req.set_queue_name(qname);
            _codec->send(_conn, req);
            waitResponse(rid);
            return ;
        }

        //发布消息
        void basicPublish(
                const std::string &ename,
                const BasicProperties *bp,
                const std::string &body) {
                std::string rid = UUIDHelper::uuid();
                basicPublishRequest req;
                req.set_rid(rid);
                req.set_cid(_cid);
                req.set_body(body);
                req.set_exchange_name(ename);
                if (bp != nullptr) {
                    req.mutable_properties()->set_id(bp->id());
                    req.mutable_properties()->set_delivery_mode(bp->delivery_mode());
                    req.mutable_properties()->set_routing_key(bp->routing_key());
                }
                _codec->send(_conn, req);
                waitResponse(rid);
                return ;
            }

        //消息确认
        void basicAck(const std::string &msgid) {
                if (_consumer.get() == nullptr) {
                    DLOG("消息确认时，找不到消费者信息！");
                    return ;
                }
                std::string rid = UUIDHelper::uuid();
                basicAckRequest req;
                req.set_rid(rid);
                req.set_cid(_cid);
                req.set_queue_name(_consumer->qname);
                req.set_message_id(msgid);
                _codec->send(_conn, req);
                waitResponse(rid);
                return;
            }
        
        //取消订阅
        void basicCancel() 
        {
            if (_consumer.get() == nullptr) 
            {
                return ;
            }
            std::string rid = UUIDHelper::uuid();
            basicCancelRequest req;
            req.set_rid(rid);
            req.set_cid(_cid);
            req.set_queue_name(_consumer->qname);
            req.set_consumer_tag(_consumer->tag);
            _codec->send(_conn, req);
            waitResponse(rid);
            _consumer.reset();
            return;
        }

        //订阅队列
        bool basicConsume(const std::string& consumer_tag, const std::string& queue_name, bool auto_ack,
                         const ConsumerCallback& cb)
        {
            if(_consumer.get() != nullptr)
            {
                DLOG("当前信道已经订阅其他队列消息");
                return false;
            }

            std::string rid = UUIDHelper::uuid();
            basicConsumeRequest req;
            req.set_rid(rid);
            req.set_cid(_cid);
            req.set_queue_name(queue_name);
            req.set_consumer_tag(consumer_tag);
            req.set_auto_ack(auto_ack);
            _codec->send(_conn, req);
            basicCommonResponsePtr resp = waitResponse(rid);
            if(resp->ok() == false)
            {
                DLOG("添加订阅失败！");
                return false;
            }
            //订阅队列以后，这个信道就成为了消费者
            _consumer = std::make_shared<Consumer>(consumer_tag, queue_name, auto_ack, cb);
            return true;
        }

        //这个连接收到响应后，就会向hash表中添加响应
        void putBasicResponse(const basicCommonResponsePtr& resp)
        {
            std::unique_lock<std::mutex> lock(_mutex);
            _basic_resp.insert(std::make_pair(resp->rid(), resp));
            _cv.notify_all();
        }

        //连接收到消息推送后，需要通过信道找到对应的消费者对象，通过回调函数进行消息处理
        void consume(const basicConsumeResponsePtr& resp) 
        {
            if (_consumer.get() == nullptr) {
                DLOG("消息处理时，未找到订阅者信息！");
                return;
            }
            if (_consumer->tag != resp->consumer_tag()) {
                DLOG("收到的推送消息中的消费者标识，与当前信道消费者标识不一致！");
                return ;
            }
            _consumer->callback(resp->consumer_tag(), resp->mutable_properties(), resp->body());
        }

    private:
        basicCommonResponsePtr waitResponse(const std::string& rid)
        {
            std::unique_lock<std::mutex> lock(_mutex);
            _cv.wait(lock, [&rid, this](){
                return _basic_resp.find(rid) != _basic_resp.end();
            });

            basicCommonResponsePtr basic_resp = _basic_resp[rid];
            _basic_resp.erase(rid);
            return basic_resp;
        }

    private:
        std::string _cid; //信道id
        muduo::net::TcpConnectionPtr _conn; // muduo的一个连接
        ProtobufCodecPtr _codec; // 协议分发器
        Consumer::ptr _consumer; //消费者
        std::mutex _mutex;
        std::condition_variable _cv;
        std::unordered_map<std::string, basicCommonResponsePtr> _basic_resp; //请求id和响应之间的一个映射关系
    };

    //对一个连接内的所有信道进行管理
    class ChannelManager
    {
    public: 
        using ptr = std::shared_ptr<ChannelManager>;
        ChannelManager()
        {}

        Channel::ptr create(const muduo::net::TcpConnectionPtr& conn, const ProtobufCodecPtr& codec)
        {
            std::unique_lock<std::mutex> lock(_mutex);
            auto channel = std::make_shared<Channel>(conn, codec); 
            _channels.insert(std::make_pair(channel->cid(), channel));
            return channel;
        }

        void remove(const std::string& cid)
        {
            std::unqiue_lock<std::mutex> lock(_mutex);
            _channels.erase(cid);
        }

        Channel::ptr get(const std::string& cid)
        {
            std::unique_lock<std::mutex> lock(_mutex);
            auto it = _channels.find(cid);
            if(it == _channels.end())
            {
                return Channel::ptr();
            }
            return it->second;
        }

    private:
        std::mutex _mutex;
        std::unordered_map<std::string, Channel::ptr> _channels;
    };
}

#endif



//客户端存在两个异步工作线程
//一个是muduo库中客户端连接的异步循环线程
//一个是收到消息后进行异步处理的工作线程池